The copper transporter Ctr1 contributes to cisplatin uptake by renal tubular cells during cisplatin nephrotoxicity

Determination of Renal Distribution of Zinc, Copper, Iron, and Platinum in Mouse Kidney Using LA-ICP-MS

The main dose-limiting side effect of cisplatin is nephrotoxicity. The utilization of cisplatin is an issue of balancing tumour toxicity versus platinum-induced nephrotoxicity. In this study, we focused on intraorgan distribution of common essential trace elements zinc, copper, and iron in healthy mouse kidneys and distribution of platinum after cisplatin treatment. Renal distribution in 12 nontreated Nu-Nu mice (males) was assessed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Furthermore, 9 Nu-Nu mice were treated with cisplatin. The order of elements concentration in kidneys was as follows: Fe > Zn > Cu. All three metals showed the higher concentrations at the cortex and medulla (28.60, 3.35, and 93.83 μg/g for Zn, Cu, and Fe, respectively) and lower concentration at the pelvis and the urinary tract (20.20, 1.93, and 62.48 μg/g for Zn, Cu, and Fe, respectively). No statistically significant difference between cortex and medulla was observed for these elements. After platinum treatment, the concentration of platinum in kidneys was enhanced more than 60-times, p < 0.001. Platinum significantly showed the highest accumulation in cortex (2.11 μg/g) with a gradient distribution. Platinum was less accumulated in medulla and pelvis than in cortex, and the lowest accumulation occurred in the urinary tract (1.13 μg/g). Image processing has been successfully utilized to colocalize metal distribution using LA-ICP-MS and histological samples images.

Panduratin A Derivative Protects against Cisplatin-Induced Apoptosis of Renal Proximal Tubular Cells and Kidney Injury in Mice

BACKGROUND

Panduratin A is a bioactive cyclohexanyl chalcone exhibiting several pharmacological activities, such as anti-inflammatory, anti-oxidative, and anti-cancer activities. Recently, the nephroprotective effect of panduratin A in cisplatin (CDDP) treatment was revealed. The present study examined the potential of certain compounds derived from panduratin A to protect against CDDP-induced nephrotoxicity.

METHODS

Three derivatives of panduratin A (DD-217, DD-218, and DD-219) were semi-synthesized from panduratin A. We investigated the effects and corresponding mechanisms of the derivatives of panduratin A for preventing nephrotoxicity of CDDP in both immortalized human renal proximal tubular cells (RPTEC/TERT1 cells) and mice.

RESULTS

Treating the cell with 10 µM panduratin A significantly reduced the viability of RPTEC/TERT1 cells compared to control (panduratin A: 72% ± 4.85%). Interestingly, DD-217, DD-218, and DD-219 at the same concentration did not significantly affect cell viability (92% ± 8.44%, 90% ± 7.50%, and 87 ± 5.2%, respectively). Among those derivatives, DD-218 exhibited the most protective effect against CDDP-induced renal proximal tubular cell apoptosis (control: 57% ± 1.23%; DD-218: 19% ± 10.14%; DD-219: 33% ± 14.06%). The cytoprotective effect of DD-218 was mediated via decreases in CDDP-induced mitochondria dysfunction, intracellular reactive oxygen species (ROS) generation, activation of ERK1/2, and cleaved-caspase 3 and 7. In addition, DD-218 attenuated CDDP-induced nephrotoxicity by a decrease in renal injury and improved in renal dysfunction in C57BL/6 mice. Importantly, DD-218 did not attenuate the anti-cancer efficacy of CDDP in non-small-cell lung cancer cells or colon cancer cells.

CONCLUSIONS

This finding suggests that DD-218, a derivative of panduratin A, holds promise as an adjuvant therapy in patients receiving CDDP.

Curcumin and its derivatives in cancer therapy: Potentiating antitumor activity of cisplatin and reducing side effects

Curcumin is a phytochemical isolated from Curcuma longa with potent tumor-suppressor activity, which has shown significant efficacy in pre-clinical and clinical studies. Curcumin stimulates cell death, triggers cycle arrest, and suppresses oncogenic pathways, thereby suppressing cancer progression. Cisplatin (CP) stimulates DNA damage and apoptosis in cancer chemotherapy. However, CP has adverse effects on several organs of the body, and drug resistance is frequently observed. The purpose of the present review is to show the function of curcumin in decreasing CP's adverse impacts and improving its antitumor activity. Curcumin administration reduces ROS levels to prevent apoptosis in normal cells. Furthermore, curcumin can inhibit inflammation via down-regulation of NF-κB to maintain the normal function of organs. Curcumin and its nanoformulations can reduce the hepatoxicity, neurotoxicity, renal toxicity, ototoxicity, and cardiotoxicity caused by CP. Notably, curcumin potentiates CP cytotoxicity via mediating cell death and cycle arrest. Besides, curcumin suppresses the STAT3 and NF-ĸB as tumor-promoting pathways, to enhance CP sensitivity and prevent drug resistance. The targeted delivery of curcumin and CP to tumor cells can be mediated nanostructures. In addition, curcumin derivatives are also able to reduce CP-mediated side effects, and increase CP cytotoxicity against various cancer types.

Current Understanding of Membrane Transporters as Regulators or Targets for Cisplatin-Induced Hearing Loss

Cisplatin is a platinum-based drug, which remains among the most efficacious anticancer treatment options. Unfortunately, use of cisplatin is hindered by dose-limiting toxicities, including irreversible hearing loss, which can grossly affect patient quality of life. Cisplatin-induced ototoxicity is the result of cochlear hair cell damage through a mechanism that is poorly understood. However, cisplatin cytotoxicity is reliant on intracellular accumulation, a process that is largely dependent on the presence of particular membrane transporters. This review will provide an update on our current understanding of the various transporters known to be involved in the disposition and cytotoxicity of platinum drugs or their metabolites, as well as their role in mediating cisplatin-induced hearing loss. We also provide a summary of the successes and opportunities in therapeutically targeting membrane transporters to alleviate platinum-induced hearing loss. Moreover, we describe how this approach could be used to reduce the severity or onset of other adverse events associated with exposure to various forms of platinum drugs, without diminishing antitumor efficacy. SIGNIFICANCE STATEMENT: Cisplatin-induced hearing loss is a dose-limiting and irreversible adverse event with no current preventative or curative treatment measures. Pharmacological targeting of membrane transporters that regulate platinum uptake into cochlear hair cells, if conducted appropriately, may alleviate this devastating side effect and could be applied to alleviate other platinum-induced toxicities.

SPHK1 contributes to cisplatin resistance in bladder cancer cells via the NONO/STAT3 axis

Sphingosine-1-phosphate (S1P) serves an important role in various physiological and pathophysiological processes, including the regulation of cell apoptosis, proliferation and survival. Sphingosine kinase 1 (SPHK1) is a lipid kinase that phosphorylates sphingosine to generate S1P. S1P has been proven to be positively correlated with chemotherapy resistance in breast cancer, colorectal carcinoma and non-small cell lung cancer. However, whether SPHK1 is involved in the development of cisplatin resistance remains to be elucidated. The present study aimed to identify the association between SPHK1 and chemoresistance in bladder cancer cells and to explore the therapeutic implications in patients with bladder cancer. Bladder cancer cell proliferation and apoptosis were determined using Cell Counting Kit-8 assays and flow cytometry, respectively. Apoptosis-related proteins were detected via western blotting. The results revealed that SPHK1 was positively correlated with cisplatin resistance in bladder cancer cells, exhibiting an antiapoptotic effect that was reflected by the downregulation of apoptosis-related proteins (Bax and cleaved caspase-3) and the upregulation of an antiapoptotic protein (Bcl-2) in SPHK1-overexpression cell lines. Suppression of SPHK1 by small interfering RNA or FTY-720 significantly reversed the antiapoptotic effect. A potential mechanism underlying SPHK1-induced cisplatin resistance and apoptosis inhibition may be activation of STAT3 via binding non-POU domain containing octamer binding. In conclusion, the present study suggested that SPHK1 displayed significant antiapoptotic effects in cisplatin-based treatment, thus may serve as a potential novel therapeutic target for the treatment for bladder cancer.

In Vitro Nephrotoxicity Studies of Established and Experimental Platinum-Based Compounds

Cisplatin is one of the most commonly used drugs for the treatment of various solid cancers. However, its efficacy is restricted by severe side effects, especially dose-limiting nephrotoxicity. New platinum-based compounds are designed to overcome this limitation. Previous investigations showed that the platinum(IV)–nitroxyl complex PN149 is highly cytotoxic in various tumor cell lines. In the present study, investigations with PN149 were extended to normal human kidney tubule epithelia. Coincident with higher intracellular platinum accumulation, the cytotoxicity of PN149 in the proximal tubule epithelial cell line ciPTEC was more pronounced compared to the established platinum chemotherapeutics cisplatin, carboplatin and oxaliplatin. Quantitative gene expression profiling revealed the induction of ROS-inducible and anti-oxidative genes, suggesting an oxidative stress response by PN149. However, in contrast to cisplatin, no pro-inflammatory response was observed. Genes coding for distinct DNA damage response factors and genes related to apoptosis were up-regulated, indicating the activation of the DNA damage response system and induction of the apoptotic cascade by PN149. Altogether, a comparable transcriptional response was observed for PN149 and the platinum chemotherapeutics. However, the lack of inflammatory activity, which is a possible cause contributing to toxicity in human renal proximal tubule epithelia, might indicate the reduced nephrotoxic potential of PN149.

miR-132-3p promotes the cisplatin-induced apoptosis and inflammatory response of renal tubular epithelial cells by targeting SIRT1 via the NF-κB pathway

Cisplatin is a highly effective and broad-spectrum anticancer drug for the clinical treatment of solid tumors. However, it causes acute kidney injury (AKI) in patients with cancer. Consequently, its clinical application is limited. The occurrence, development, and prognosis of AKI are closely associated with microRNA (miRNA), which needs validation as a biomarker, especially for the early stages of cisplatin-induced AKI. An example of miRNA is miR-132-3p, which plays important roles in inflammatory responses, cell proliferation, and apoptosis in a variety of diseases. However, variations in its expression, potential mechanisms, and downstream targets in cisplatin-induced AKI remain unclear. This study aimed to investigate the functions of miR-132-3p in cisplatin-induced AKI. Sequencing and qRT-PCR revealed that miR-132-3p was significantly upregulated in cisplatin-induced AKI models of mouse and human proximal renal tubular epithelial (HK-2) cells. Apoptosis and inflammatory responses were significantly suppressed by the inhibition of the miR-132-3p expression in cisplatin-stimulated HK-2 cells, and this suppression was blocked by miR-132-3p mimics. Bioinformatics and dual luciferase reporter gene assay identified the 3'- UTR of SIRT1 mRNA as a direct target of miR-132-3p. RNA-FISH and immunofluorescence co-localization demonstrated that miR-132-3p and SIRT1 directly combined and interacted in the cytoplasm of HK-2 cells. Mechanistically, the SIRT1 expression was suppressed and the NF-κB signaling pathway was activated by the upregulation of miR-132-3p in cisplatin-induced AKI. By contrast, the SIRT1 expression was upregulated after the inhibition of miR-132-3p. The ratios of p-p65/p65 and p-IκBα/IκBα were significantly reduced, and the expression levels of inflammatory biomarkers and apoptotic proteins induced by cisplatin were obviously attenuated. Our results suggested that miR-132-3p exacerbated cisplatin-induced AKI by negatively regulating SIRT1 and activating the NF-κB signaling pathway. Therefore, targeting miR-132-3p might be a potential adjuvant therapy for ameliorating AKI in cisplatin-treated patients.

Preferential Cochleotoxicity of Cisplatin

Cisplatin-induced ototoxicity in humans is more predominant in the cochlea than in the vestibule. Neither definite nor substantial vestibular dysfunction after cisplatin treatment has been consistently reported in the current literature. Inner ear hair cells seem to have intrinsic characteristics that make them susceptible to direct exposure to cisplatin. The existing literature suggests, however, that cisplatin might have different patterns of drug trafficking across the blood-labyrinth-barrier, or different degrees of cisplatin uptake to the hair cells in the cochlear and vestibular compartments. This review proposes an explanation for the preferential cochleotoxicity of cisplatin based on current evidence as well as the anatomy and physiology of the inner ear. The endocochlear potential, generated by the stria vascularis, acting as the driving force for hair cell mechanoelectrical transduction might also augment cisplatin entry into cochlear hair cells. Better understanding of the stria vascularis might shed new light on cochleotoxic mechanisms and inform the development of otoprotective interventions to moderate cisplatin associated ototoxicity.

Germacrone Reduces Cisplatin-Induced Toxicity of Renal Proximal Tubular Cells via Inhibition of Organic Cation Transporter

Cisplatin is a widely used chemotherapy for solid tumors; however, its benefits are limited by serious nephrotoxicity, particularly in proximal tubular cells. The present study investigated the renoprotective effect and mechanisms of germacrone, a bioactive terpenoid compound found in Curcuma species on cisplatin-induced toxicity of renal cells. Germacrone (50 and 100 µM) attenuated apoptosis of human renal proximal tubular cells, RPTEC/TERT1 following treatment with 50 µM cisplatin and for 48 h. Co-treating RPTEC/TERT1 cells with cisplatin and germacrone significantly reduced cellular platinum content compared with cisplatin treatment alone. The effect of germacrone on organic cation transporter 2 (OCT2) which is a transporter responsible for cisplatin uptake was determined. Germacrone showed an inhibitory effect on OCT2-mediated methyl-4-phenylpyridinium acetate (³H-MPP⁺) uptake with IC₅₀ of 15 µM with less effect on OCT1. The germacrone's protective effect on cisplatin-induced cytotoxicity was not observed in cancer cells; cisplatin's anti-cancer activity was preserved. In conclusion, germacrone prevents cisplatin-induced toxicity in renal proximal tubular cells via inhibition OCT2 transport function and reducing cisplatin accumulation. Thus germacrone may be a good candidate agent used for reducing cisplatin-induced nephrotoxicity.

Association of Urine Platinum With Acute Kidney Injury in Children Treated With Cisplatin for Cancer

Cisplatin is a chemotherapeutic agent highly excreted in urine and known to cause acute kidney injury (AKI). As AKI diagnosis by serum creatinine (SCr) is usually delayed, endeavors for finding early AKI biomarkers continue. This study aims to determine if urine platinum (UP) concentration 24 hours after cisplatin infusion is associated with AKI, and to evaluate the association between urine platinum and tubular damage biomarkers: neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1). Children treated with cisplatin in 12 Canadian centers (April 2013 to December 2017) were included. Urine from the morning after the first cisplatin infusion of the first or second cisplatin cycle was measured for urine platinum, NGAL, and KIM-1. SCr and serum electrolytes were used to detect AKI by either SCr elevation or urinary electrolyte wasting (potassium, magnesium, phosphate). The associations of urine platinum with AKI, NGAL, and KIM-1 were assessed. A total of 115 participants (54% boys, median age, 8.5 years; interquartile range, 4.0-13.4) were included, of which 29 (25%) and 105 (91%) developed AKI defined by SCr and electrolyte criteria, respectively. Higher urine platinum was associated with higher cisplatin dose (Spearman rho, 0.21) and with younger age (Spearman rho, -0.33). Urine platinum was not associated with postinfusion AKIor KIM-1, but was weakly associated with NGAL, particularly in participants without SCr AKI (Pearson's r, 0.22). Urine platinum may be a marker of mild tubular injury but is not likely to be a useful biomarker of clinically evident AKI.

Na/H Exchange Regulatory Factor 1 Deficient Mice Show Evidence of Oxidative Stress and Altered Cisplatin Pharmacokinetics

(1) Background: One third of patients who receive cisplatin develop an acute kidney injury. We previously demonstrated the Na/H Exchange Regulatory Factor 1 (NHERF1) loss resulted in increased kidney enzyme activity of the pentose phosphate pathway and was associated with more severe cisplatin nephrotoxicity. We hypothesized that changes in proximal tubule biochemical pathways associated with NHERF1 loss alters renal metabolism of cisplatin or response to cisplatin, resulting in exacerbated nephrotoxicity. (2) Methods: 2-4 month-old male wild-type and NHERF1 knock out littermate mice were treated with either vehicle or cisplatin (20 mg/kg dose IP), with samples taken at either 4, 24, or 72 h. Kidney injury was determined by urinary neutrophil gelatinase-associated lipocalin and histology. Glutathione metabolites were measured by HPLC and genes involved in glutathione synthesis were measured by qPCR. Kidney handling of cisplatin was assessed by a kidney cortex measurement of γ-glutamyl transferase activity, Western blot for γ-glutamyl transferase and cysteine S-conjugate beta lyase, and ICP-MS for platinum content. (3) Results: At 24 h knock out kidneys show evidence of greater tubular injury after cisplatin and exhibit a decreased reduced/oxidized glutathione ratio under baseline conditions in comparison to wild-type. KO kidneys fail to show an increase in γ-glutamyl transferase activity and experience a more rapid decline in tissue platinum when compared to wild-type. (4) Conclusions: Knock out kidneys show evidence of greater oxidative stress than wild-type accompanied by a greater degree of early injury in response to cisplatin. NHERF1 loss has no effect on the initial accumulation of cisplatin in the kidney cortex but is associated with an altered redox status which may alter the activity of enzymes involved in cisplatin metabolism.

MiR-3168, miR-6125, and miR-4718 as potential predictors of cisplatin-induced nephrotoxicity in patients with head and neck cancer

Background

No biomarker is available for identifying cancer patients at risk of developing nephrotoxicity when treated with cisplatin.

Methods

We performed microRNA (miRNA) sequencing using plasma collected 5 days after cisplatin treatment (D5) from twelve patients with head and neck cancer with and without nephrotoxicity (grade ≥ 2 increased serum creatinine). The most differentially expressed miRNAs between the two groups were selected for quantification at baseline and D5 in a larger cohort of patients. The association between miRNAs and nephrotoxicity was evaluated by calculating the odds ratio (OR) from univariate logistic regression. Receiver operating characteristic curves (ROC) were used to estimate the area under the curve (AUC), sensitivity, and specificity.

Results

MiR-3168 (p = 1.98 × 10^− 8), miR-4718 (p = 4.24 × 10^− 5), and miR-6125 (p = 6.60 × 10^− 5) were the most differentially expressed miRNAs and were further quantified in 43, 48, and 53 patients, respectively. The baseline expression of miR-3168 (p = 0.0456, OR = 1.03, 95% CI: 1.00–1.06) and miR-4718 (p = 0.0388, OR = 1.56, 95% CI: 1.03–2.46) were associated with an increased risk of nephrotoxicity, whereas miR-6125 showed a trend (p = 0.0618, OR = 1.73, 95% CI: 0.98–3.29). MiR-4718 showed the highest AUC (0.77, 95% CI: 0.61–0.93) with sensitivity of 66.76 and specificity of 79.49.

Conclusions

We have provided evidence of baseline plasmatic expression of miR-3168, miR-6125, and miR-4718 as potential predictors of cisplatin-induced nephrotoxicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08317-2.

Cisplatin chemotherapy and renal function

Cisplatin has been a mainstay of cancer chemotherapy since the 1970s. Despite its broad anticancer potential, its clinical use has regularly been constrained by kidney toxicities. This review details those biochemical pathways and metabolic conversions that underlie the kidney toxicities. A wide range of redox events contribute to the eventual physiological consequences of drug activities.

Regulated cell death in cisplatin-induced AKI: relevance of myo-inositol metabolism

Regulated cell death (RCD), distinct from accidental cell death, refers to a process of well-controlled programmed cell death with well-defined pathological mechanisms. In the past few decades, various terms for RCDs were coined, and some of them have been implicated in the pathogenesis of various types of acute kidney injury (AKI). Cisplatin is widely used as a chemotherapeutic drug for a broad spectrum of cancers, but its usage was hampered because of being highly nephrotoxic. Cisplatin-induced AKI is commonly seen clinically, and it also serves as a well-established prototypic model for laboratory investigations relevant to acute nephropathy affecting especially the tubular compartment. Literature reports over a period of three decades have indicated that there are multiple types of RCDs, including apoptosis, necroptosis, pyroptosis, ferroptosis, and mitochondrial permeability transition-mediated necrosis, and some of them are pertinent to the pathogenesis of cisplatin-induced AKI. Interestingly, myo-inositol metabolism, a vital biological process that is largely restricted to the kidney, seems to be relevant to the pathogenesis of certain forms of RCDs. A comprehensive understanding of RCDs in cisplatin-induced AKI and their relevance to myo-inositol homeostasis may yield novel therapeutic targets for the amelioration of cisplatin-related nephropathy.

Mechanisms of Cisplatin-Induced Acute Kidney Injury: Pathological Mechanisms, Pharmacological Interventions, and Genetic Mitigations

Administration of the chemotherapeutic agent cisplatin leads to acute kidney injury (AKI). Cisplatin-induced AKI (CIAKI) has a complex pathophysiological map, which has been linked to cellular uptake and efflux, apoptosis, vascular injury, oxidative and endoplasmic reticulum stress, and inflammation. Despite research efforts, pharmaceutical interventions, and clinical trials spanning over several decades, a consistent and stable pharmacological treatment option to reduce AKI in patients receiving cisplatin remains unavailable. This has been predominately linked to the incomplete understanding of CIAKI pathophysiology and molecular mechanisms involved. Herein, we detail the extensively known pathophysiology of cisplatin-induced nephrotoxicity that manifests and the variety of pharmacological and genetic alteration studies that target them.

Advances in Our Understanding of the Molecular Mechanisms of Action of Cisplatin in Cancer Therapy

Cisplatin and other platinum-based chemotherapeutic drugs have been used extensively for the treatment of human cancers such as bladder, blood, breast, cervical, esophageal, head and neck, lung, ovarian, testicular cancers, and sarcoma. Cisplatin is commonly administered intravenously as a first-line chemotherapy for patients suffering from various malignancies. Upon absorption into the cancer cell, cisplatin interacts with cellular macromolecules and exerts its cytotoxic effects through a series of biochemical mechanisms by binding to Deoxyribonucleic acid (DNA) and forming intra-strand DNA adducts leading to the inhibition of DNA synthesis and cell growth. Its primary molecular mechanism of action has been associated with the induction of both intrinsic and extrinsic pathways of apoptosis resulting from the production of reactive oxygen species through lipid peroxidation, activation of various signal transduction pathways, induction of p53 signaling and cell cycle arrest, upregulation of pro-apoptotic genes/proteins, and down-regulation of proto-oncogenes and anti-apoptotic genes/proteins. Despite great clinical outcomes, many studies have reported substantial side effects associated with cisplatin monotherapy, while others have shown substantial drug resistance in some cancer patients. Hence, new formulations and several combinational therapies with other drugs have been tested for the purpose of improving the clinical utility of cisplatin. Therefore, this review provides a comprehensive understanding of its molecular mechanisms of action in cancer therapy and discusses the therapeutic approaches to overcome cisplatin resistance and side effects.

HIF in Nephrotoxicity during Cisplatin Chemotherapy: Regulation, Function and Therapeutic Potential

Simple Summary

Cisplatin is a widely used chemotherapy drug, but its use and efficacy are limited by its nephrotoxicity. HIF has protective effects against kidney injury during cisplatin chemotherapy, but it may attenuate the anti-cancer effect of cisplatin. In this review, we describe the role and regulation of HIF in cisplatin-induced nephrotoxicity and highlight the therapeutic potential of targeting HIF in chemotherapy.

Abstract

Cisplatin is a highly effective, broad-spectrum chemotherapeutic drug, yet its clinical use and efficacy are limited by its side effects. Particularly, cancer patients receiving cisplatin chemotherapy have high incidence of kidney problems. Hypoxia-inducible factor (HIF) is the “master” transcription factor that is induced under hypoxia to trans-activate various genes for adaptation to the low oxygen condition. Numerous studies have reported that HIF activation protects against AKI and promotes kidney recovery in experimental models of cisplatin-induced acute kidney injury (AKI). In contrast, little is known about the effects of HIF on chronic kidney problems following cisplatin chemotherapy. Prolyl hydroxylase (PHD) inhibitors are potent HIF inducers that recently entered clinical use. By inducing HIF, PHD inhibitors may protect kidneys during cisplatin chemotherapy. However, HIF activation by PHD inhibitors may reduce the anti-cancer effect of cisplatin in tumors. Future studies should test PHD inhibitors in tumor-bearing animal models to verify their effects in kidneys and tumors.

Dabigatran mitigates cisplatin-mediated nephrotoxicity through down regulation of thrombin pathway

Introduction

Cisplatin (CDDP) nephrotoxicity is one of the most significant complications limiting its use in cancer therapy.

Objectives

This study investigated the pivotal role played by thrombin in CDDP-mediated nephrotoxicity. This work also aimed to clarify the possible preventive effect of Dabigatran (Dab), a direct thrombin inhibitor, on CDDP nephrotoxicity.

Methods

Animals were grouped as follow; normal control group, CDDP nephrotoxicity group, CDDP + Dab 15, and CDDP + Dab 25 groups. Four days following CDDP administration, blood and urine samples were collected to evaluate renal function. Moreover, tissue samples were collected from the kidney to determine apoptosis markers, oxidative stress and histopathological evaluation. An immunofluorescence analysis of tissue factor (TF), thrombin, protease-activated receptor-2 (PAR2), fibrin, pERK1/2 and P53 proteins expression was also performed.

Results

Thrombin, pERK, cleaved caspase-3, and oxidative stress markers were significantly elevated in CDDP-treated group. However, pretreatment of animals with either low or high doses of Dab significantly improved kidney function and decreased oxidative stress and apoptotic markers.

Conclusion

We conclude that thrombin is an important factor in the pathogenesis of CDDP kidney toxicity via activation of ERK1/2, P53 and caspase-3 pathway, which can be effectively blocked by Dab.

Daphnetin Attenuated Cisplatin-Induced Acute Nephrotoxicity With Enhancing Antitumor Activity of Cisplatin by Upregulating SIRT1/SIRT6-Nrf2 Pathway

Cisplatin (CDDP) is a widely used drug for cancer treatment that exhibits major side effects in normal tissues, such as nephrotoxicity in kidneys. The Nrf2 signaling pathway, a regulator of mitochondrial dysfunction, oxidative stress and inflammation, is a potential therapeutic target in CDDP-induced nephrotoxicity. We explored the underlying mechanisms in wild-type (WT) and Nrf2^−/− mice on CDDP-induced renal dysfunction in vivo. We found that Nrf2 deficiency aggravated CDDP-induced nephrotoxicity, and Daph treatment significantly ameliorated the renal injury characterized by biochemical markers in WT mice and reduced the CDDP-induced cell damage. In terms of the mechanism, Daph upregulated the SIRT1 and SIRT6 expression in vivo and in vitro. Furthermore, Daph inhibited the expression level of NOX4, whereas it activated Nrf2 translocation and antioxidant enzymes HO-1 and NQO1, and alleviated oxidative stress and mitochondrial dysfunction. Moreover, Daph suppressed CDDP-induced NF-κB and MAPK inflammation pathways, as well as p53 and cleaved caspase-3 apoptosis pathways. Notably, the protective effects of Daph in WT mice were completely abrogated in Nrf2^−/− mice. Moreover, Daph enhanced, rather than attenuated, the tumoricidal effect of CDDP.

A Multicompartment Human Kidney Proximal Tubule-on-a-Chip Replicates Cell Polarization-Dependent Cisplatin Toxicity

Drug-induced kidney injury is a major clinical problem and causes drug attrition in the pharmaceutical industry. To better predict drug-induced kidney injury, kidney in vitro cultures with enhanced physiologic relevance are developed. To mimic the proximal tubule, the main site of adverse drug reactions in the kidney, human-derived renal proximal tubule epithelial cells (HRPTECs) were injected in one of the channels of dual-channel Nortis chips and perfused for 7 days. Tubes of HRPTECs demonstrated expression of tight junction protein 1 (zona occludens-1), lotus lectin, and primary cilia with localization at the apical membrane, indicating an intact proximal tubule brush border. Gene expression of cisplatin efflux transporters multidrug and toxin extrusion transporter (MATE) 1 (SLC47A1) and MATE2-k (SLC47A2) and megalin endocytosis receptor increased 19.9 ± 5.0-, 23.2 ± 8.4-, and 106 ± 33-fold, respectively, in chip cultures compared with 2-dimensional cultures. Moreover, organic cation transporter 2 (OCT2) (SLC22A2) was localized exclusively on the basolateral membrane. When infused from the basolateral compartment, cisplatin (25 µM, 72 hours) induced toxicity, which was evident as reduced cell number and reduced barrier integrity compared with vehicle-treated chip cultures. Coexposure with the OCT2 inhibitor cimetidine (1 mM) abolished cisplatin toxicity. In contrast, infusion of cisplatin from the apical compartment did not induce toxicity, which was in line with polarized localization of cisplatin uptake transport proteins, including OCT2. In conclusion, we developed a dual channel human kidney proximal tubule-on-a-chip with a polarized epithelium, restricting cisplatin sensitivity to the basolateral membrane and suggesting improved physiologic relevance over single-compartment models. Its implementation in drug discovery holds promise to improve future in vitro drug-induced kidney injury studies. SIGNIFICANCE STATEMENT: Human-derived kidney proximal tubule cells retained characteristics of epithelial polarization in vitro when cultured in the kidney-on-a-chip, and the dual-channel construction allowed for drug exposure using the physiologically relevant compartment. Therefore, cell polarization-dependent cisplatin toxicity could be replicated for the first time in a kidney proximal tubule-on-a-chip. The use of this physiologically relevant model in drug discovery has potential to aid identification of safe novel drugs and contribute to reducing attrition rates due to drug-induced kidney injury.

Role for Drug Transporters in Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and dose-limiting toxicity to widely used chemotherapeutics. Although the exact molecular mechanism of chemotherapy-induced peripheral neuropathy remains elusive, there is consensus that it is caused by damage to the peripheral nervous system leading to sensory symptoms. Recently developed methodologies have provided evidence of expression of drug transporters in the peripheral nervous system. In this literature review, we explore the role for drug transporters in CIPN. First, we assessed the transport of chemotherapeutics that cause CIPN (taxanes, platins, vincristine, bortezomib, epothilones, and thalidomide). Second, we cross-referenced the transporters implicated in genetic or functional studies with CIPN with their expression in the peripheral nervous system. Several drug transporters are involved in the transport of chemotherapeutics that cause peripheral neuropathy and particularly efflux transporters, such as ABCB1 and ABCC1, are expressed in the peripheral nervous system. Previous literature has linked genetic variants in efflux transporters to higher risk of peripheral neuropathy with the taxanes paclitaxel and docetaxel and the vinca alkaloid vincristine. We propose that this might be due to accumulation of the chemotherapeutics in the peripheral nervous system due to reduced neuronal efflux capacity. Thus, concomitant administration of efflux transporter inhibitors may lead to higher risk of adverse events of drugs that cause CIPN. This might prove valuable in drug development where screening new drugs for neurotoxicity might also require drug transporter consideration. There are ongoing efforts targeting drug transporters in the peripheral nervous system to reduce intraneuronal concentrations of chemotherapeutics that cause CIPN, which might ultimately protect against this dose-limiting adverse event.

Polysulfide and Hydrogen Sulfide Ameliorate Cisplatin-Induced Nephrotoxicity and Renal Inflammation through Persulfidating STAT3 and IKKβ

Cisplatin, a widely used chemotherapy for the treatment of various tumors, is clinically limited due to its extensive nephrotoxicity. Inflammatory response in tubular cells is a driving force for cisplatin-induced nephrotoxicity. The plant-derived agents are widely used to relieve cisplatin-induced renal dysfunction in preclinical studies. Polysulfide and hydrogen sulfide (H₂S) are ubiquitously expressed in garlic, and both of them are documented as potential agents for preventing and treating inflammatory disorders. This study was designed to determine whether polysulfide and H₂S could attenuate cisplatin nephrotoxicity through suppression of inflammatory factors. In renal proximal tubular cells, we found that sodium tetrasulfide (Na₂S₄), a polysulfide donor, and sodium hydrosulfide (NaHS) and GYY4137, two H₂S donors, ameliorated cisplatin-caused renal toxicity through suppression of the massive production of inflammatory cytokines, including tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2). Mechanistically, the anti-inflammatory actions of Na₂S₄ and H₂S may be mediated by persulfidation of signal transducer and activator of transcription 3 (STAT3) and inhibitor kappa B kinase β (IKKβ), followed by decreased phosphorylation of STAT3 and IKKβ. Moreover, the nuclear translocation of nuclear transcription factor kappa B (NF-κB), and phosphorylation and degradation of nuclear factor kappa B inhibitor protein alpha (IκBα) induced by cisplatin, were also mitigated by both polysulfide and H₂S. In mice, after treatment with polysulfide and H₂S donors, cisplatin-associated renal dysfunction was strikingly ameliorated, as evidenced by measurement of serum blood urea nitrogen (BUN) and creatinine levels, renal morphology, and the expression of renal inflammatory factors. Our present work suggests that polysulfide and H₂S could afford protection against cisplatin nephrotoxicity, possibly via persulfidating STAT3 and IKKβ and inhibiting NF-κB-mediated inflammatory cascade. Our results might shed light on the potential benefits of garlic-derived polysulfide and H₂S in chemotherapy-induced renal damage.

Diversity of dose-individualization and therapeutic drug monitoring practices of platinum compounds: a review

Introduction: Platinum-derived drugs are commonly used for the treatment of solid tumors. The differences in chemical structures of these molecules lead to different pharmacological properties, in terms of indication, efficacy, and toxicity. Their pharmacokinetics (PK) differ according to their respective renal elimination and have led to many studies investigating their dose optimization. Area covered: This review attempts to summarize and compare PK and pharmacodynamics of cisplatin, carboplatin, and oxaliplatin, with an emphasis on differences of dose calculations and opportunities for therapeutic drug monitoring (TDM) in various patient populations. Expert opinion: Although cisplatin and carboplatin can be considered as analogs since they share the same DNA interacting properties, the slower hydrolysis of the latter results in a better safety profile. Carboplatin is the only drug in oncology to be administrated according to a target area under the curve of concentration versus time, considering that its PK variability is almost fully explained by renal function, not by body size. This enables individual dosing based on predicted carboplatin clearance (along with patients renal characteristics) or on actual clearance with TDM, especially in a high-dose protocol.

Organic Cation Transporters in Health and Disease

The organic cation transporters (OCTs) OCT1, OCT2, OCT3, novel OCT (OCTN)1, OCTN2, multidrug and toxin exclusion (MATE)1, and MATE kidney-specific 2 are polyspecific transporters exhibiting broadly overlapping substrate selectivities. They transport organic cations, zwitterions, and some uncharged compounds and operate as facilitated diffusion systems and/or antiporters. OCTs are critically involved in intestinal absorption, hepatic uptake, and renal excretion of hydrophilic drugs. They modulate the distribution of endogenous compounds such as thiamine, L-carnitine, and neurotransmitters. Sites of expression and functions of OCTs have important impact on energy metabolism, pharmacokinetics, and toxicity of drugs, and on drug-drug interactions. In this work, an overview about the human OCTs is presented. Functional properties of human OCTs, including identified substrates and inhibitors of the individual transporters, are described. Sites of expression are compiled, and data on regulation of OCTs are presented. In addition, genetic variations of OCTs are listed, and data on their impact on transport, drug treatment, and diseases are reported. Moreover, recent data are summarized that indicate complex drug-drug interaction at OCTs, such as allosteric high-affinity inhibition of transport and substrate dependence of inhibitor efficacies. A hypothesis about the molecular mechanism of polyspecific substrate recognition by OCTs is presented that is based on functional studies and mutagenesis experiments in OCT1 and OCT2. This hypothesis provides a framework to imagine how observed complex drug-drug interactions at OCTs arise. Finally, preclinical in vitro tests that are performed by pharmaceutical companies to identify interaction of novel drugs with OCTs are discussed. Optimized experimental procedures are proposed that allow a gapless detection of inhibitory and transported drugs.

SOX9 promotes stress-responsive transcription of VGF nerve growth factor inducible gene in renal tubular epithelial cells

Acute kidney injury (AKI) is a common clinical condition associated with diverse etiologies and abrupt loss of renal function. In patients with sepsis, rhabdomyolysis, cancer, and cardiovascular disorders, the underlying disease or associated therapeutic interventions can cause hypoxia, cytotoxicity, and inflammatory insults to renal tubular epithelial cells (RTECs), resulting in the onset of AKI. To uncover stress-responsive disease-modifying genes, here we have carried out renal transcriptome profiling in three distinct murine models of AKI. We find that Vgf nerve growth factor inducible gene up-regulation is a common transcriptional stress response in RTECs to ischemia-, cisplatin-, and rhabdomyolysis-associated renal injury. The Vgf gene encodes a secretory peptide precursor protein that has critical neuroendocrine functions; however, its role in the kidneys remains unknown. Our functional studies show that RTEC-specific Vgf gene ablation exacerbates ischemia-, cisplatin-, and rhabdomyolysis-associated AKI in vivo and cisplatin-induced RTEC cell death in vitro Importantly, aggravation of cisplatin-induced renal injury caused by Vgf gene ablation is partly reversed by TLQP-21, a Vgf-derived peptide. Finally, in vitro and in vivo mechanistic studies showed that injury-induced Vgf up-regulation in RTECs is driven by the transcriptional regulator Sox9. These findings reveal a crucial downstream target of the Sox9-directed transcriptional program and identify Vgf as a stress-responsive protective gene in kidney tubular epithelial cells.

Efficient Drug Screening and Nephrotoxicity Assessment on Co-culture Microfluidic Kidney Chip

The function and susceptibility of various drugs are tested with renal proximal tubular epithelial cells; yet, replicating the morphology and kidneys function using the currently available in vitro models remains difficult. To overcome this difficulty, in the study presented in this paper, a device and a three-layer microfluidic chip were developed, which provides a simulated environment for kidney organs. This device includes two parts: (1) microfluidic drug concentration gradient generator and (2) a flow-temperature controlled platform for culturing of kidney cells. In chip study, renal proximal tubular epithelial cells (RPTECs) and peritubular capillary endothelial cells (PCECs) were screened with the drugs to assess the drug-induced nephrotoxicity. Unlike cells cultured in petri dishes, cells cultured in the microfluidic device exhibited higher performance in terms of both cell growth and drug nephrotoxicity evaluation. It is worth mentioning that a significant decrease in cisplatin-induced nephrotoxicity was found because of the intervention of cimetidine in the microfluidic device. In conclusion, the different in the cell performance between the microfluidic device and the petri dishes demonstrates the physiological relevance of the nephrotoxicity screening technology along with the microfluidic device developed in this study. Furthermore, this technology can also facilitate the development of reliable kidney drugs and serve as a useful and efficient test-bed for further investigation of the drug nephrotoxicity evaluation.

Ribociclib mitigates cisplatin-associated kidney injury through retinoblastoma-1 dependent mechanisms

Aberrant cell cycle activation is a hallmark of carcinogenesis. Recently three cell cycle targeting cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have been approved for the treatment of metastatic breast cancer. CDK4/6 inhibitors suppress proliferation through inhibition of CDK4/6-dependent retinoblastoma-1 (Rb1) phosphorylation and inactivation, a key regulatory step in G1-to-S-phase transition. Importantly, aberrant cell cycle activation is also linked with several non-oncological diseases including acute kidney injury (AKI). AKI is a common disorder caused by toxic, inflammatory, and ischemic damage to renal tubular epithelial cells (RTECs). Interestingly, AKI triggered by the anti-cancer drug cisplatin can be mitigated by ribociclib, a CDK4/6 inhibitor, through mechanisms that remain unclear. Employing in vivo cell cycle analysis and functional Rb1 knock-down, here, we have examined the cellular and pharmacological basis of the renal protective effects of ribociclib during cisplatin nephrotoxicity. Remarkably, siRNA-mediated Rb1 silencing or RTEC-specific Rb1 gene ablation did not alter the severity of cisplatin-associated AKI; however, it completely abrogated the protective effects conferred by ribociclib administration. Furthermore, we find that cisplatin treatment evokes CDK4/6 activation and Rb1 phosphorylation in the normally quiescent RTECs, however, this is not followed by S-phase entry likely due to DNA-damage induced G1 arrest. The cytoprotective effects of ribociclib are thus not a result of suppression of S-phase entry but are likely dependent on the maintenance of Rb1 in a hypo-phosphorylated and functionally active form under stress conditions. These findings delineate the role of Rb1 in AKI and illustrate the pharmacological basis of the renal protective effects of CDK4/6 inhibitors.

Canagliflozin reduces cisplatin uptake and activates Akt to protect against cisplatin-induced nephrotoxicity

Cisplatin is a widely used chemotherapy drug with notorious nephrotoxicity. Na⁺-glucose cotransporter 2 inhibitors are a class of novel antidiabetic agents that may have other effects in the kidneys besides blood glucose control. In the present study, we demonstrated that canagliflozin significantly attenuates cisplatin-induced nephropathy in C57BL/6 mice and suppresses cisplatin induced renal proximal tubular cell apoptosis in vitro. The protective effect of canagliflozin was associated with inhibition of p53, p38 and JNK activation. Mechanistically, canagliflozin partially reduced cisplatin uptake by kidney tissues in mice and renal tubular cells in culture. In addition, canagliflozin enhanced the activation of Akt and inhibited the mitochondrial pathway of apoptosis during cisplatin treatment. The protective effect of canagliflozin was diminished by the phosphatidylinositol 3-kinase/Akt inhibitor LY294002. Notably, canagliflozin did not affect the chemotherapeutic efficacy of cisplatin in A549 and HCT116 cancer cell lines. These results suggest a new application of canagliflozin for renoprotection in cisplatin chemotherapy. Canagliflozin may protect kidneys by reducing cisplatin uptake and activating cell survival pathways.

Evaluation of cisplatin-induced injury in human kidney organoids

Acute kidney injury (AKI) remains a major global healthcare problem, and there is a need to develop human-based models to study AKI in vitro. Toward this goal, we have characterized induced pluripotent stem cell-derived human kidney organoids and their response to cisplatin, a chemotherapeutic drug that induces AKI and preferentially damages the proximal tubule. We found that a single treatment with 50 µM cisplatin induces hepatitis A virus cellular receptor 1 (HAVCR1) and C-X-C motif chemokine ligand 8 (CXCL8) expression, DNA damage (γH2AX), and cell death in the organoids but greatly impairs organoid viability. DNA damage was not specific to the proximal tubule but also affected the distal tubule and interstitial cell populations. This lack of specificity correlated with low expression of proximal tubule-specific SLC22A2/organic cation transporter 2 (OCT2) for cisplatin. To improve viability, we developed a repeated low-dose regimen of 4 × 5 µM cisplatin over 7 days and found this caused less toxicity while still inducing a robust injury response that included secretion of known AKI biomarkers and inflammatory cytokines. This work validates the use of human kidney organoids to model aspects of cisplatin-induced injury, with the potential to identify new AKI biomarkers and develop better therapies.

Links between cancer metabolism and cisplatin resistance

Cisplatin is one of the most potent and widely used chemotherapeutic agent in the treatment of several solid tumors, despite the high toxicity and the frequent relapse of patients due to the onset of drug resistance. Resistance to chemotherapeutic agents, either intrinsic or acquired, is currently one of the major problems in oncology. Thus, understanding the biology of chemoresistance is fundamental in order to overcome this challenge and to improve the survival rate of patients. Studies over the last 30 decades have underlined how resistance is a multifactorial phenomenon not yet completely understood. Recently, tumor metabolism has gained a lot of interest in the context of chemoresistance; accumulating evidence suggests that the rearrangements of the principal metabolic pathways within cells, contributes to the sensitivity of tumor to the drug treatment. In this review, the principal metabolic alterations associated with cisplatin resistance are highlighted. Improving the knowledge of the influence of metabolism on cisplatin response is fundamental to identify new possible metabolic targets useful for combinatory treatments, in order to overcome cisplatin resistance.

Treating Patients With Locally Advanced Squamous Cell Carcinoma of the Head and Neck Unsuitable to Receive Cisplatin-Based Therapy

Concurrent chemoradiotherapy with high-dose cisplatin (100 mg/m² every 3 weeks) is the preferred regimen with curative intent for patients with unresected locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). This treatment is associated with acute and late toxicities, including myelosuppression, severe nausea/vomiting, irreversible renal failure, hearing loss, and neurotoxicity. Because of cisplatin's safety profile, treatment adherence to high-dose cisplatin can be suboptimal. Patients commonly receive less than the total cumulative target dose of 300 mg/m² or the minimum recommended dose of 200 mg/m², which can have a negative impact on locoregional control and survival. Alternatively, cetuximab plus radiotherapy may be most suitable for patients at high risk of non-adherence to high-dose cisplatin. We discuss the baseline characteristics dictating the unsuitability/borderline unsuitability of cisplatin and the available alternative evidence-based treatment regimens for patients with LA SCCHN. We non-systematically reviewed published phase II and III trials and retrospective analyses of high-dose cisplatin-based chemoradiation in LA SCCHN conducted between 1987 and 2018, focusing on recent key phase III studies. We defined the baseline characteristics and associated prescreening tests to determine unsuitability and borderline unsuitability for high-dose cisplatin in combination with radiotherapy in patients with LA SCCHN. Patients with any pre-existing comorbidities that may be exacerbated by high-dose cisplatin treatment can be redirected to a non-cisplatin-based option to minimize the risk of treatment non-adherence. High-dose cisplatin plus radiotherapy remains the preferred treatment for fit patients with unresected LA SCCHN; patients who are unsuitable or borderline unsuitable for high-dose cisplatin could be identified using available tests for potential comorbidities and should be offered alternative treatments, such as cetuximab plus radiotherapy.

Alteration of Metal Elements in Radiation Injury: Radiation-Induced Copper Accumulation Aggravates Intestinal Damage

Ionizing radiation causes damage to a variety of tissues, especially radiation-sensitive tissues, such as the small intestine. Radiation-induced damage is caused primarily by increased oxidative stress in the body. Studies have shown that trace metal elements play an irreplaceable role in oxidative stress in humans, which may be associated with radiation-induced tissue damage. However, the alteration and functional significance of trace metal elements in radiation-induced injury is not clear. In this study, we explored the association between radiation-induced damage and 7 trace metal elements in mouse models. We found that the concentration of zinc and copper in mice serum was decreased significantly after irradiation, whereas that of nickel, manganese, vanadium, cobalt, and stannum was not changed by inductively coupled plasma mass spectrometry. The role of copper in radiation-induced intestines was characterized in detail. The concentration of copper was increased in irradiated intestine but reduced in irradiated heart. Immunohistochemistry staining showed that copper transporter protein copper transport 1 expression was upregulated in irradiated mouse intestine, suggesting its potential involvement in radiation-induced copper accumulation. At the cellular level, the addition of CuCl2potentiated radiation-induced reactive oxygen species in intestine-derived human intestinal epithelial cell and IEC-6 cells. Moreover, the level of copper in damaged cells may be related to the severity of radiation-induced damage as evidenced by a cell viability assay. These results indicate that copper may be involved in the progression of radiation-induced tissue damage and may be a potential therapeutic target.

Increase in Protective Effect of Panax vietnamensis by Heat Processing on Cisplatin-Induced Kidney Cell Toxicity

Cisplatin is a platinum-based anticancer agent used for treating a wide range of solid cancers. One of the side effects of this drug is its severe nephrotoxicity, limiting the safe dose of cisplatin. Therefore, many natural products have been studied and applied to attenuate the toxicity of this compound. In this study, we found that steamed Vietnamese ginseng (Panax vietnamensis) could significantly reduce the kidney damage of cisplatin in an in vitro model using porcine proximal tubular LLC-PK1 kidney cells. From processed ginseng under optimized conditions (120 °C, 12 h), we isolated seven compounds (20(R,S)-ginsenoside Rh2, 20(R,S)-ginsenoside Rg3, ginsenoside Rk1, ginsenoside-Rg5, and ocotillol genin) that showed kidney-protective potential against cisplatin toxicity. By comparing the 50% recovery concentration (RC₅₀), the R form of ginsenoside, Rh2 and Rg3, had RC₅₀ values of 6.67 ± 0.42 µM and 8.39 ± 0.3 µM, respectively, while the S forms of ginsenoside, Rh2 and Rg3, and Rk1, had weaker protective effects, with RC₅₀ ranging from 46.15 to 88.4 µM. G-Rg5 and ocotillol, the typical saponin of Vietnamese ginseng, had the highest RC₅₀ (180.83 ± 33.27; 226.19 ± 66.16, respectively). Our results suggest that processed Vietnamese gingseng (PVG), as well as those compounds, has the potential to improve kidney damage due to cisplatin toxicity.

The dietary isoflavone daidzein mitigates oxidative stress, apoptosis, and inflammation in CDDP-induced kidney injury in rats: Impact of the MAPK signaling pathway

Cisplatin-induced nephrotoxicity persists as a clinical problem despite several supportive measures to alleviate renal damage. Daidzein (DZ), a dietary isoflavone having antioxidant and anti-inflammatory activity, is investigated in this study for protective effects against cisplatin-induced renal injury in rats. DZ (25, 50, or 100 mg/kg; intraperitoneally; 10 days) was administered along with Cisplatin, single dose, on the 7th day of the experiment. On the 11th day, the rats were euthanized, and different samples were collected for analysis. Biochemical, histopathological, and molecular parameters were assessed to evaluate the effect of daidzein. Cisplatin injection resulted in renal dysfunction, lipid peroxidation that led to consumption of antioxidants, exaggerated apoptosis, and inflammation. These changes were associated with increase in the signaling proteins. DZ attenuated the toxic effects of cisplatin on the kidney at 100 mg/kg dose. The study concludes with the finding that daidzein imparts protection against the nephrotoxic effect of Cisplatin and can be considered as a novel, potential therapy.

Paradoxical Effect of Grape Pomace Extract on Cisplatin-Induced Acute Kidney Injury in Rats

Cisplatin is one of the most used drugs in the therapy of different types of cancer. However, its use is limited by nephrotoxicity. This study investigated the effects of a commercially available grape pomace extract (GE) from Vitis vinifera on cisplatin-induced kidney toxicity in rats. Sixty-four male Wistar albino rats were randomly divided into eight groups. Groups 1–3 were controls, receiving 0.9% saline and doses 1 and 2 of GE respectively. Cisplatin was given to groups 4–8. Two groups received pretreatment with GE, while another two groups received pre- and post-treatment with GE. Blood samples were collected and all animals sacrificed. Kidneys were harvested for histopathological analysis. GE significantly increased blood creatinine and urea levels, the severity of kidney histopathological damage, and mortality in all cisplatin groups, except for group 7 which received pre- and post-treatment with a low dose of GE. Renal toxicity was determined by mortality and severe histopathological renal lesions. Additionally, the serum total antioxidant capacity (TAC) was not significantly modified in the treated groups compared to the control. These results indicate that the GE did not have a protective effect on cisplatin-induced nephrotoxicity; on the contrary, GE accentuated the toxic effect of cisplatin.

Correlation of prechemotherapy urinary megalin ectodomain (A-megalin) levels with the development of cisplatin-induced nephrotoxicity: a prospective observational study

Background

Cisplatin is a potent chemotherapeutic agent used to treat a variety of solid tumors. One of the major side effects of cisplatin is dose-limiting nephrotoxicity. We recently demonstrated that the renal uptake of cisplatin and resultant cisplatin-induced nephrotoxicity are mediated in part by megalin, an endocytic receptor in proximal tubule epithelial cells (PTECs). We also developed sandwich enzyme-linked immunosorbent assays to measure the megalin ectodomain (A-megalin) and full-length megalin (C-megalin) in urine using monoclonal antibodies against the amino- and carboxyl-termini of megalin, respectively. The present study examined the correlation of urinary megalin level with cisplatin-induced nephrotoxicity and its utility as a biomarker in patients with thoracic cancer.

Methods

This prospective observational study involved 45 chemotherapy-naïve patients scheduled to receive chemotherapy with ≥60 mg/m² cisplatin for histologically diagnosed small cell lung cancer, non-small cell lung cancer, or malignant pleural mesothelioma. Before and after the first course of chemotherapy, we measured urinary A- and C-megalin and other markers of PTEC injury, such as N-acetyl-β-D-glucosaminidase, α₁-microglobulin, β₂-microglobulin, neutrophil gelatinase-associated lipocalin, and liver-type fatty acid-binding protein, and compared the values with the change in the estimated glomerular filtration rate (eGFR) and clinical risk factors for renal impairment.

Results

A negative correlation was found between baseline urinary A-megalin levels and change in eGFR (r = − 0.458, P = 0.002). According to Kaplan–Meier survival curves, eGFR decline was associated with the baseline urinary A-megalin quartile (P = 0.038). In addition, according to the hazard ratios (HRs) for eGFR decline > 10 mL/min/1.73 m² calculated using a Cox proportional hazard model, the highest quartile had a significantly higher risk of eGFR decline compared with the lowest quartile (HR 7.243; 95% confidence interval 1.545–33.962). Other baseline urinary markers showed no correlation with eGFR decline.

Conclusions

This is the first report demonstrating that prechemotherapy urinary A-megalin levels are correlated with the development of cisplatin-induced nephrotoxicity. This finding has clinical implications for the identification of patients at risk for cisplatin-induced nephrotoxicity and the development of possible prophylactic therapies.

Cadmium exposure enhances organic cation transporter 2 trafficking to the kidney membrane and exacerbates cisplatin nephrotoxicity

Renal accumulation and exposure of cadmium originating from pollution in agricultural land and the prevalence of cigarette smoking remains an unneglectable human health concern. Whereas cadmium exposure has been correlated with increased incidence of a variety of kidney diseases, little is known pertaining to its effect on renal drug disposition and response in patients. Here, we report that cadmium exposure significantly increased the activity of organic cation transporter 2 (OCT2), a critical renal drug transporter recommended in United States Federal Drug Administration guidance for assessment during drug development. Cadmium enhanced OCT2 trafficking to the cell membrane both in vitro and in vivo. Mechanistically cadmium-mediated OCT2 translocation was found to involve protein-protein interaction between serine/threonine-protein kinase AKT2, calcium/calmodulin and the AKT substrate AS160 in in vitro cellular studies. The formed protein complex could selectively facilitate phosphorylation of AKT2 at T309, which induced translocation of OCT2 to the plasma membrane. Moreover, cadmium exposure markedly exacerbated nephrotoxicity induced by cisplatin, an OCT2 substrate, by increasing its accumulation in the mouse kidney. Consistently, there was a significant correlation between plasma cadmium level and alteration of renal function in cervical cancer patients who underwent chemotherapy with cisplatin. Thus, our studies suggest that membrane transporter distribution induced by cadmium exposure is a previously unrecognized factor for the broad variation in renal drug disposition and response.

Mice with a Sertoli cell-specific knockout of the Ctr1 gene exhibit a reduced sensitivity to cisplatin-induced testicular germ cell apoptosis

Exposure to the chemotherapeutic agent cis-diamminedichloroplatinum(ii) (cDDP) is well known to instigate acute and prolonged testicular injury in male patients.

Exposure to the chemotherapeutic agent cis-diamminedichloroplatinum(ii) (cDDP) is well known to instigate acute and prolonged testicular injury in male patients. Many investigators have hypothesized that cDDP-induced dysfunction of Sertoli cells (SCs) may, in part, account for the cDDP-induced lasting testicular injury. Nevertheless, the relative contribution of cDDP-induced SC injury versus direct effects on germ cells (GCs) to the pathogenesis of GC loss remains to be elucidated. The expression of the copper transporter 1 (CTR1) protein in cells directly corresponds with cDDP uptake and its cellular toxicity. Therefore, to discern the role of SCs in the pathogenic mechanism, mice were developed with a SC-specific disruption of the Ctr1 gene (SC^ΔCtr1) as a strategy to prevent their exposure to cDDP. Adult mice at postnatal day (PND) 60 were treated with 5 mg kg^–1 cDDP and then testis collected at 48 hours. A two-fold increase in GC-apoptosis occurred in the testis of cDDP-treated wildtype (WT) mice as compared to saline-treated WT mice. In contrast, cDDP-treated SC^ΔCtr1 mice exhibited only a half-fold increase in GC-apoptosis as compared to the saline-treated SC^ΔCtr1 mice. This reduced incidence of GC apoptosis in the SC^ΔCtr1 mice corresponded to a significantly lower level of platinum within the testis. Taken together, these findings reveal that the uptake of cDDP by CTR1 in SCs accounts for the accumulation of cDDP in the testis and plays a pivotal role in the pathogenic sequence of events leading to the loss of germ cells via apoptosis.

Protective Role of Natural Products in Cisplatin-Induced Nephrotoxicity

Cisplatin is a widely used antineoplastic agent for the treatment of metastatic tumors, advanced bladder cancer and many other solid tumors. However, at higher doses, toxicities such as nephrotoxicity may appear. Cisplatin leads to DNA damage and subsequently renal cell death. Besides that, oxidative stress is also implicated as one of the main causes of nephrotoxicity. Several studies showed that numerous natural products: ginseng, curcumin, licorice, honey and pomegranate were able to reduce the oxidative stress by restoring the levels of antioxidant enzymes and also at the same time act as an anti-inflammatory agent. Furthermore, pre-treatment with vitamin supplementation, such as vitamin C, E and riboflavin markedly decreased serum urea and increased the levels of antioxidant enzymes in the kidney even after cisplatin induction in cancer patients. These natural products possess potent antioxidant and anti-inflammatory medicinal properties, and they can be safely used as a supplementary regime or combination therapy against cisplatin-induced nephrotoxicity. The present review focused on the protective role of a few natural products which is widely used in folk medicines in cisplatin-induced nephrotoxicity.

New Insights in the Pathogenesis of Cisplatin-Induced Nephrotoxicity

Cisplatin (cis-diamminedichloroplatinum II) is a widely used chemotherapeutic agent. However, efficacy and clinical utility of this drug is significantly limited by severe side effects such as nephrotoxicity which develops due to renal accumulation and bio-transformation in proximal tubular epithelial cells. Cisplatin-induced nephrotoxicity can be manifested as acute kidney injury (AKI), or as different types of tubulopathies, salt wasting, loss of urinary concentrating ability, and magnesium wasting. The attenuation of cisplatin-caused AKI is currently accomplished by hydration, magnesium supplementation or mannitol-induced forced diuresis. However, mannitol treatment causes over-diuresis and consequent dehydration, indicating an urgent need for the clinical use of newly designed, safe and efficacious renoprotective drug, as an additive therapy for high dose cisplatin-treated patients. Accordingly, we emphasized current knowledge regarding molecular mechanisms responsible for cisplatin-caused nephrotoxicity and we described in detail the main clinical manifestations of cisplatin-induced renal dysfunction in order to pave the way for the design of new therapeutic approaches that can minimize detrimental effects of cisplatin in the kidneys. Having in mind that most of cisplatin-induced cytotoxic effects against renal cells are, at the same time, involved in anti-tumor activity of cisplatin, new nephroprotective therapeutic strategies have to prevent renal injury and inflammation without affecting cisplatin-induced toxicity against malignant cells.

Clinical prospects of biomarkers for the early detection and/or prediction of organ injury associated with pharmacotherapy

Several biomarkers are used to monitor organ damage caused by drug toxicity. Traditional markers of kidney function, such as serum creatinine and blood urea nitrogen are commonly used to estimate glomerular filtration rate. However, these markers have several limitations including poor specificity and sensitivity. A number of serum and urine biomarkers have recently been described to detect kidney damage caused by drugs such as cisplatin, gentamicin, vancomycin, and tacrolimus. Neutrophil gelatinase-associated lipocalin (NGAL), liver-type fatty acid-binding protein (L-FABP), kidney injury molecule-1 (KIM-1), monocyte chemotactic protein-1 (MCP-1), and cystatin C have been identified as biomarkers for early kidney damage. Hy's Law is widely used as to predict a high risk of severe drug-induced liver injury caused by drugs such as acetaminophen. Recent reports have indicated that glutamate dehydrogenase (GLDH), high-mobility group box 1 (HMGB-1), Keratin-18 (k18), MicroRNA-122 and ornithine carbamoyltransferase (OCT) are more sensitive markers of hepatotoxicity compared to the traditional markers including the blood levels of amiotransferases and total bilirubin. Additionally, the rapid development of proteomic technologies in biofluids and tissue provides a new multi-marker panel, leading to the discovery of more sensitive biomarkers. In this review, an update topics of biomarkers for the detection of kidney or liver injury associated with pharmacotherapy.

A glance at molecular mechanisms underlying cisplatin-induced nephrotoxicity and possible renoprotective strategies: a narrative review

Cisplatin is a platinum-based drug that is usually used for the treatment of many carcinomas. However, it comes with several devastating side effects, including nephrotoxicity. Cisplatin toxicity is a very complex process, which is exacerbated by the accumulation of cisplatin in renal tubular cells via passive diffusion and transporter-mediated processes. Once cisplatin enters these cells, it induces the formation of reactive oxygen species that cause cellular damage, including DNA damage, inflammation, and eventually cell death. On a small scale, these damages can be mitigated by cellular antioxidant defense mechanism. However, on a large scale, such as in chemotherapy, this defense mechanism may fail, resulting in nephrotoxicity. The current article reviews the molecular mechanisms underlying cisplatin-induced nephrotoxicity and possible renoprotective strategies to determine novel therapeutic interventions for alleviating this toxicity.

Advances in Toxicological Research of the Anticancer Drug Cisplatin

Cisplatin is one of the most widely used chemotherapeutic agents for various solid tumors in the clinic due to its high efficacy and broad spectrum. The antineoplastic activity of cisplatin is mainly due to its ability to cross-link with DNA, thus blocking transcription and replication. Unfortunately, the clinical use of cisplatin is limited by its severe, dose-dependent toxic side effects. There are approximately 40 specific toxicities of cisplatin, among which nephrotoxicity is the most common one. Other common side effects include ototoxicity, neurotoxicity, gastrointestinal toxicity, hematological toxicity, cardiotoxicity, and hepatotoxicity. These side effects together reduce the life quality of patients and require lowering the dosage of the drug, even stopping administration, thus weakening the treatment effect. Few effective measures exist clinically against these side effects because the exact mechanisms of various side effects from cisplatin remain still unclear. Therefore, substantial effort has been made to explore the complicated biochemical processes involved in the toxicology of cisplatin, aiming to identify effective ways to reduce or eradicate its toxicity. This review summarizes and reviews the updated advances in the toxicological research of cisplatin. We anticipate to provide insights into the understanding of the mechanisms underlying the side effects of cisplatin and designing comprehensive therapeutic strategies involving cisplatin.

Recent Advances in Models, Mechanisms, Biomarkers, and Interventions in Cisplatin-Induced Acute Kidney Injury

Cisplatin is a widely used chemotherapeutic agent used to treat solid tumours, such as ovarian, head and neck, and testicular germ cell. A known complication of cisplatin administration is acute kidney injury (AKI). The development of effective tumour interventions with reduced nephrotoxicity relies heavily on understanding the molecular pathophysiology of cisplatin-induced AKI. Rodent models have provided mechanistic insight into the pathophysiology of cisplatin-induced AKI. In the subsequent review, we provide a detailed discussion of recent advances in the cisplatin-induced AKI phenotype, principal mechanistic findings of injury and therapy, and pre-clinical use of AKI rodent models. Cisplatin-induced AKI murine models faithfully develop gross manifestations of clinical AKI such as decreased kidney function, increased expression of tubular injury biomarkers, and tubular injury evident by histology. Pathways involved in AKI include apoptosis, necrosis, inflammation, and increased oxidative stress, ultimately providing a translational platform for testing the therapeutic efficacy of potential interventions. This review provides a discussion of the foundation laid by cisplatin-induced AKI rodent models for our current understanding of AKI molecular pathophysiology.

Molecular mechanisms of cisplatin-induced nephrotoxicity: a balance on the knife edge between renoprotection and tumor toxicity

Background

Cisplatin (cis-diamminedichloroplatinum II, CDDP) is one of the most effective chemotherapeutic agents. However, its clinical use is limited due to the severe side effects, including nephrotoxicity and acute kidney injury (AKI) which develop due to renal accumulation and biotransformation of CDDP. The alleviation or prevention of CDDP-caused nephrotoxicity is currently accomplished by hydration, magnesium supplementation or mannitol-induced forced diuresis which is considered for high-dose CDDP-treated patients. However, mannitol treatment causes over-diuresis and consequent dehydration in CDDP-treated patients, indicating an urgent need for the clinical use of safe and efficacious renoprotective drug as an additive therapy for high dose CDDP-treated patients.

Main body

In this review article we describe in detail signaling pathways involved in CDDP-induced apoptosis of renal tubular cells, oxidative stress and inflammatory response in injured kidneys in order to pave the way for the design of new therapeutic approaches that can minimize CDDP-induced nephrotoxicity. Most of these molecular pathways are, at the same time, crucially involved in cytotoxic activity of CDDP against tumor cells and potential alterations in their function might mitigate CDDP-induced anti-tumor effects.

Conclusion

Despite the fact that many molecules were designated as potential therapeutic targets for renoprotection against CDDP, modulation of CDDP-induced nephrotoxicity still represents a balance on the knife edge between renoprotection and tumor toxicity.

Pathologic Perspectives on Acute Tubular Injury Assessment in the Kidney Biopsy

The molecular mechanisms in acute tubular injury (ATI) are complex and enigmatic. Moreover, we currently lack validated tissue injury markers that can be integrated into the kidney biopsy analysis to guide nephrologists in their patient's management of AKI. Although recognizing the ATI lesion by light microscopy is fairly straightforward, the staging of tubular lesions in the context of clinical time course and etiologic mechanism currently is not adapted to the renal pathology practice. To the clinician, the exact time point when an ischemic or toxic injury has occurred often is not known and cannot be discerned from the review of the biopsy sample. Moreover, the assessment of the different types of organized necrosis as the underlying cell death mechanism, which can be targeted using specific inhibitors, has not yet reached clinical practice. The renal pathology laboratory is uniquely qualified to assess the time course and etiology of ATI using established analytic techniques, such as immunohistochemistry and electron microscopy. Recent advances in the understanding of pathophysiological mechanisms of ATI and the important role that certain types of tubular cell organelles play in different stages of the ATI lesions may allow differentiation of early versus late ATI. Furthermore, the determination of respective cell injury pathways may help to differentiate ischemic versus toxic etiology in a reliable fashion. In the future, such a kidney biopsy-based classification system of ATI could guide the nephrologist's management of patients in regard to treatment modality and drug choice.

Protective Smell of Hydrogen Sulfide and Polysulfide in Cisplatin-Induced Nephrotoxicity

Though historically known as a toxic gas, hydrogen sulfide (H₂S) has displayed a new face as the third endogenous gaseous signaling molecule after nitric oxide (NO) and carbon monoxide (CO). Here in this review, we survey the role and therapeutic potential of H₂S in cisplatin-induced nephrotoxicity. Specifically, reduction of H₂S by cystathionine γ-lyase (CSE) downregulation upon cisplatin treatment may contribute to cisplatin-induced renal cell injury, possibly by augmentation of endogenous reactive oxygen species (ROS) production, while H₂S donation may prevent subsequent renal dysfunction by inhibiting NADPH oxidase activation. Intriguingly, H₂S slow-releasing compound GYY4137 seems to increase the anticancer activity of cisplatin, at least in several cancer cell lines, and this is probably due to its own anticancer effect. However, the efficacy of H₂S donors in tumor-bearing animals remains to be tested in terms of renal protection and cancer inhibition after receiving cisplatin. Furthermore, accumulative evidence regarding usage of polysulfide, a novel H₂S derived molecule, in the therapy of cisplatin-induced nephrotoxicity, was also summarized.

INNATE IMMUNITY IN NEPHROTOXIC ACUTE KIDNEY INJURY

Acute kidney injury (AKI) is common among hospitalized patients and is associated with high morbidity and mortality. Inflammation is recognized to play an important role in both ischemic and toxic models of AKI. Cisplatin is a widely used and highly effective cancer chemotherapeutic agent but carries the risk of nephrotoxicity. We have used a model of cisplatin-induced AKI to explore the functions of the innate immune response in kidney injury. Several components of innate immunity, such as Toll-like receptor sensing and inflammatory cytokine production, contribute to both ischemic and cisplatin-induced AKI. Importantly, it is the activity of these components in kidney parenchymal cells, rather than immune cells, which mediate AKI. Cellular components of innate immunity, such as neutrophils and dendritic cells, appear to play disparate roles in ischemic vs toxic AKI. Innate immune pathways could be targeted to prevent or treat AKI.